Student of Timelines

Equilibrium 3 - {2}{u} ({2}{u}: Exile this card with 3 time counters on it. At the beginning of your upkeep, remove a time counter from it. As long as there are no time counters on it, you may cast it without paying its mana cost anytime you could cast an instant.)
Whenever a time counter is removed from Student of Timelines while it's exiled, target player chooses untap step, upkeep step, or draw step. That player skips his or her next chosen
step.